在做采集时：采集对方的数据时：一定要用POST的提交方式，请问用POST如何使用代理IP呢，我是这样写的，但是报操作超时的异常

try
{
Encoding encoding = Encoding.GetEncoding("utf-8");
Uri uri = new Uri(action);
byte[] paramBytes = encoding.GetBytes(parmString);
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(uri);

if (ip != "")
{
WebProxy proxyObject = new WebProxy(ip, port);
wr.Proxy = proxyObject;
wr.Timeout = 5000;
}

wr.ContentType = "application/x-www-form-urlencoded";
wr.Method = "POST";
using (Stream stream = wr.GetRequestStream())
{
stream.Write(paramBytes, 0, paramBytes.Length);
}
WebResponse webResponse = wr.GetResponse();
using(StreamReader reader = new StreamReader(webResponse.GetResponseStream(), encoding))
{
return reader.ReadToEnd();
}
}
catch (Exception ex)
{
return ex.Message;
}